SILVER SOLUBILITY IN YBA2CU3OX

Ceramic YBa2Cu3Ox samples with different amounts of nominally added silver(0.5; 1.0; 1.5; 2.5; 5 and 10 wt.%) have been studied using X-ray diffraction, SEM, EDS and WDS techniques. Silver appears to be present within the grains. The Ag concentration increases with the nominally added Ag then saturates at the nominal Ag concentrations > 2.5 wt.%. The solid solubility of silver in YBa2Cu3Ox sintered in air at 950 degrees C for 24 h then annealed in oxygen at 500 degrees C for 24 h, has a saturation level, similar to 0.37 wt.% at room temperature, and the corresponding y value is 0.023 of YBa2Cu3-yAgyOx. The lattice parameters of the orthorhombic unit cell, a and c, are found to increase with increasing Ag concentration, whereas the lattice parameter b remains the same for all the samples with different Ag contents and has the value of the pure YBa2Cu3Ox specimen. The noticeable changes in the a and c lattice parameters were linked with the Ag substitution for Cu in YBa2Cu3O ceramics.